Chicago Has The Koch Brothers To Thank For Its Toxic Black Dust Problem

In what environmentalists in Chicago are calling a "shameful switcheroo," it appears Chicago Mayor Rahm Emanuel may have had a change of heart when it comes to petcoke, the mostly-carbon and sulfur black dust that has been roiling the city's Southeast Side since last fall.

"Those are exactly the kind of facilities we don’t want in our communities. They’re opening the door to that," Salazar argued.

While Emanuel pledged in February that he would "make sure the ordinance puts up a 'not wanted' sign in the City of Chicago as it relates to petcoke," a spokesman for the mayor told the Tribune the exemption was necessary because "we do not want to preclude companies who use petcoke in their manufacturing processes from locating in the city."

Petcoke is a byproduct of the oil refining process, and mounds of the stuff have been piling up along the Calumet River in Chicago and blowing into nearby residential areas, raising environmental concerns. Unlike dirt, petcoke leaves behind a residue and can cause health problems like coughing, wheezing and shortness of breath, in addition to aggravating existing respiratory conditions like asthma, the Chicago Department of Public Health reports.